Compact 517 MHz soliton mode-locked Er-doped fiber ring laser

We report on a compact passive mode-locked Er:fiber ring laser operated at the fundamental repetition rate of 517 MHz, which we believe is the highest fundamental repetition rate ever reported in a ring cavity fiber laser. The key technique is the employment of two innovative high-power wavelength domain multiplexer collimators with all gain fiber cavity suited for the high power (up to 2 W) pumping. The laser is featured with a direct chirpfree output pulse, which is 97 fs without extracavity c